Perovskite precursor solution based on addition of 1-thioglycerol and solar cell

Abstract

The invention discloses a perovskite precursor solution based on addition of 1-thioglycerol and a solar cell. 0.01-0.5 mg / mL of 1-thioglycerol is added into the perovskite precursor solution, so that the defect of elemental I2 is reduced, the deterioration of the perovskite material is inhibited, and the preservation period of the perovskite precursor solution is prolonged. The perovskite thin film is prepared in the air by using the precursor solution added with the 1-thioglycerol, so that the dependence of perovskite thin film preparation on inert atmosphere is solved, meanwhile, the grain size of the perovskite thin film can be increased, the grain boundary can be reduced, the stability and the photoelectric property can be improved, and the formation of metal Pb0 defects can be inhibited. A solar cell prepared based on the perovskite thin film can continuously, reversibly and dynamically repair the defects of a device in the whole life cycle of preparation and service by means of a redox shuttle system constructed by 1-thioglycerol, and the photoelectric conversion efficiency and stability of the perovskite solar cell are improved.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor technology, and in particular relates to a perovskite precursor solution and a solar cell based on the addition of 1-thioglycerol. Background Art

[0002] Perovskite solar cells have attracted widespread attention in recent years due to their advantages such as high photoelectric conversion efficiency, low cost and solution preparation. However, the soft lattice ion characteristics of perovskite materials make them prone to degradation in air environments, resulting in poor photoelectric performance of the prepared devices. In addition, the I⁻ ions in the perovskite precursor solution are easily oxidized in the air, resulting in the iodine I 2 and I 3 ⁻ ions, which in turn cause the collapse of the perovskite lattice and the formation of defects, as well as the corrosion of the metal electrode. The further generation of metal Pb 0 As deep energy level defects, they can lead to non-radiative recombination of photogenerated carriers, seriously damaging the optoelectronic performance of the device.

[0003] The existing method is to use freshly prepared non-deteriorated perovskite precursor solution and spin-coat the perovskite film in a glove box filled with inert gas to prevent moisture and oxygen in the air from damaging the perovskite material, and to repair defects through post-interface treatment strategies. This will undoubtedly increase the cost and steps of device preparation, including the cost of solution deterioration, the cost of inert gas, and the cost of glove box equipment.

[0004] By adding reducing agents such as formate, vitamin C, and trap-based derivative materials to the perovskite precursor solution, the oxidation of I⁻ to I can be effectively inhibited. 2 However, this type of reducing agent is a sacrificial agent, that is, the reducing agent material itself is I 2 Or 2 After oxidation, it can no longer perform its ability to repair defects, and it is also unable to repair the defects that are continuously generated during the preparation and service life of perovskite solar cells.

[0005] In view of this, it is of great practical significance to develop a method that can extend the shelf life of perovskite precursor solution, stably prepare perovskite solar cells in an air environment, and continuously repair defects in the device throughout its entire life cycle of preparation and service. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention proposes a perovskite precursor solution and a solar cell based on the addition of 1-thioglycerol. By introducing a trace amount of reducing agent 1-thioglycerol (1-ThL) into the perovskite precursor solution, on the one hand, the deterioration of the perovskite material can be inhibited to extend the shelf life of the perovskite precursor solution, and on the other hand, the dependence of the preparation of perovskite films on an inert atmosphere can be solved, thereby stably preparing perovskite solar cells in an air environment. In addition, the redox shuttle system constructed with 1-thioglycerol can be used to continuously and reversibly dynamically repair the defects of the device during the entire life cycle of preparation and service, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0007] A perovskite precursor solution based on 1-thioglycerol addition, wherein the perovskite precursor solution is a perovskite component precursor solution or PbI 2 solution and ammonium salt solution, the concentration of added 1-thioglycerol is 0.01~0.5 mg / mL.

[0008] Preferably, the perovskite component is PbI 2 , or PbI 2 With PbBr 2 , CsI, and CsBr, and the ammonium salt is a combination of multiple ones of FAI, MAI, MABr, and MACl.

[0009] A method for preparing a perovskite film based on 1-thioglycerol addition, preparing a perovskite precursor solution based on 1-thioglycerol addition, and spin-coating the perovskite component precursor solution in a one-step method, or spin-coating the perovskite PbI in sequence in the air in a two-step method 2 Solutions and ammonium salt solutions.

[0010] The solar cells based on 1-thioglycerol addition were prepared in air by solution spin coating using a perovskite precursor solution to which 1-thioglycerol was added.

[0011] The preparation method of the solar cell based on the addition of 1-thioglycerol is to deposit an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode on the surface of a transparent conductive substrate in the air in sequence to obtain a formal solar cell. The perovskite layer is obtained by spin coating a perovskite precursor solution to which 1-thioglycerol is added.

[0012] Preferably, a hole transport layer, a perovskite layer, an electron transport layer and a metal electrode are sequentially deposited on the surface of a transparent conductive substrate to obtain an inverted solar cell.

[0013] Preferably, the electron transport layer is formed by TiO 2 SnO 2 、ZnO 2 , C 60、PC 61 A film made of one or more composite materials in BM.

[0014] Preferably, the hole transport layer is Spiro-OMeTAD, PTAA or NiO x Film made of material.

[0015] Preferably, the metal electrode is one of gold, silver and copper.

[0016] The present invention has the following beneficial effects: 1. This method can greatly extend the shelf life of the perovskite precursor solution by adding a trace amount of 1-thioglycerol to the perovskite precursor solution, and can also solve the dependence on inert atmosphere during the preparation of perovskite films, thereby reducing the investment costs of perovskite solar cell preparation in terms of perovskite precursor solution deterioration loss, inert gas consumption and glove box equipment procurement.

[0017] 2. Additive 1-thioglycerol can not only reduce the element I 2 Defects, the product disulfide can also oxidize metal Pb 0 Deep energy level defects can regulate the stoichiometric balance of perovskite components. And disulfide can return to the 1-thioglycerol state and continue to reduce the continuously generated I 2 / I 3 - Defects, and so on, construct a reversible redox shuttle system, which realizes the dynamic repair of defects throughout the entire life cycle of perovskite solar cell preparation and service. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The UV-visible absorption spectra of the ammonium salt solutions in Comparative Example 1 and Example 1 are shown; Figure 2 The scanning electron microscope images of the perovskite films in Comparative Example 1 and Example 1; Figure 3 X-ray diffraction patterns of the perovskite films in Comparative Example 1 and Example 1; Figure 4 Steady-state fluorescence spectra of the perovskite films in Comparative Example 1 and Example 1; Figure 5 This is a comparison diagram of the water contact angle of the perovskite film in Comparative Example 1 and Example 1; Figure 6 X-ray photoelectron spectra of the aged perovskite films in Comparative Example 1 and Example 1; Figure 7 Metal Pb powder and I before and after adding 1-thioglycerol 2 Comparison chart of reaction results; Figure 8 1 is a current density-voltage curve diagram of the perovskite solar cell in Comparative Example 1 and Example 1; Fig. 9 This is a stability change trend chart of the perovskite solar cells in Comparative Example 1 and Example 1. DETAILED DESCRIPTION

[0019] The present invention will be further explained below with reference to the accompanying drawings;

[0020] Comparative Example 1 This example prepares a perovskite precursor solution and a formal solar cell without the addition of 1-thioglycerol as a comparative example. The specific steps are as follows: Step 1: ultrasonically clean the transparent conductive substrate with deionized water, acetone and ethanol in sequence, and perform plasma treatment on the transparent conductive substrate after drying.

[0021] Step 2: Spin-coat a layer of SnO on the surface of the plasma-treated transparent conductive substrate. 2 The film was then annealed at 150°C for 30 minutes to obtain an electron transport layer.

[0022] Step 3: PbI 2 and CsBr were dissolved in N,N-dimethylformamide and dimethyl sulfoxide mixed in a volume ratio of 9:1, PbI 2 The concentration of is 1.5 mol / L, the concentration of CsBr is 0.04 mol / L, and PbI 2 Precursor solution.

[0023] FAI and MACl were dissolved in isopropanol, the concentration of FAI was 90 mg / mL, and the concentration of MACl was 9 mg / mL, to obtain an ammonium salt solution.

[0024] Step 4: Spin-coat PbI on the surface of the electron transport layer at a speed of 1500 rpm 2 The precursor solution was then annealed at 70°C for 60 seconds to form PbI 2 Then on PbI 2 The film surface was spin-coated with an ammonium salt solution at a rotation speed of 1800 rpm, and then annealed at 150° C. for 20 minutes to obtain a perovskite film.

[0025] Step 5: Spin-coat a layer of Spiro-OMeTAD film on the surface of the perovskite film to obtain a hole transport layer. Evaporate a silver metal electrode on the surface of the hole transport layer to obtain a formal solar cell based on the addition of 1-thioglycerol.

[0026] Example 1

[0027] This embodiment prepares a perovskite precursor solution and a formal solar cell based on the addition of 1-thioglycerol, and the specific steps are as follows: Step 1: ultrasonically clean the transparent conductive substrate with deionized water, acetone and ethanol in sequence, and perform plasma treatment on the transparent conductive substrate after drying.

[0028] Step 2: Spin-coat a layer of SnO on the surface of the plasma-treated transparent conductive substrate. 2 The film was then annealed at 150°C for 30 minutes to obtain an electron transport layer.

[0029] Step 3: PbI 2 , CsBr and 1-ThL were dissolved in N,N-dimethylformamide and dimethyl sulfoxide mixed in a volume ratio of 9:1, and PbI 2 The concentration of 1-thioglycerol was 1.5 mol / L, the concentration of CsBr was 0.04 mol / L, and the concentration of 1-thioglycerol was 0.1 mg / mL. 2 Precursor solution.

[0030] FAI, MACl and 1-ThL were dissolved in isopropanol. The concentration of FAI was 90 mg / mL, the concentration of MACl was 9 mg / mL, and the concentration of 1-thioglycerol was 0.1 mg / mL, to obtain an ammonium salt solution to which 1-thioglycerol was added.

[0031] The UV-visible absorption spectra of the ammonium salt solutions prepared in Comparative Example 1 and Example 1 were measured at 0, 7 and 14 days of aging, respectively. The results are as follows: Figure 1 As shown. Figure 1 It can be seen that after the solution of Comparative Example 1 was placed for 14 days, a large characteristic peak appeared at a wavelength of 360nm, forming a large amount of I 2 / I 3 ⁻, the solution has deteriorated. However, in Example 1 after adding the reducing agent 1-ThL, there is basically no characteristic peak at a wavelength of 360nm, that is, there is basically no I 2 / I 3 The formation of ⁻ demonstrates the excellent ability of 1-ThL to extend the storage period of the perovskite precursor solution.

[0032] Step 4: Spin-coat the perovskite component precursor solution with 1-thioglycerol added on the surface of the electron transport layer at a speed of 1500 rpm, and then anneal at 70°C for 60 seconds to form PbI 2 Then on PbI 2 The film surface was spin-coated with an ammonium salt solution with 1-thioglycerol added at a rotation speed of 1800 rpm, and then annealed at 150° C. for 20 minutes to obtain a perovskite film.

[0033] The comparison results of the scanning electron microscope image, X-ray diffraction image and steady-state fluorescence spectrum of the perovskite film prepared in Comparative Example 1 and Example 1 are as follows: Figure 2 , 3 , 4. Figure 2 It can be seen that the perovskite crystal particle size in Comparative Example 1 is mostly concentrated below 1 micron, and there are a large number of crystals less than 0.5 micron in size. In Example 1, the perovskite film prepared from the perovskite precursor solution after adding 1-thioglycerol generally has a perovskite crystal particle size exceeding 1 micron. That is, the perovskite film after the 1-thioglycerol additive is optimized has larger grains and fewer grain boundaries. In addition, the incompletely reacted PbI in the perovskite film that induces the degradation of the perovskite film 2 Less, fewer perovskite defects, which helps improve stability. Figure 3 It can be seen that the (110) crystal plane of the perovskite film at 2θ=14.2° in Example 1 is significantly enhanced, indicating that the perovskite crystal quality is improved, which is beneficial to the improvement of the photoelectric performance of the prepared perovskite solar cell. Figure 4 It can be seen that the PL fluorescence intensity of the perovskite film prepared in Example 1 is significantly enhanced compared with that in Comparative Example 1, indicating that the addition of 1-thioglycerol can reduce non-radiative recombination by passivating perovskite defects, including the inhibition of defect formation and the repair of defects.

[0034] The water contact angles of the perovskite films prepared in Comparative Example 1 and Example 1 were measured. Figure 5 As shown, the hydrophobicity of the perovskite film prepared in Example 1 is 69°, which is higher than 59° in Comparative Example 1, indicating that the addition of 1-thioglycerol can make the perovskite film have more excellent hydrophobic properties, which is helpful for the preparation of the film in an air environment and the stability of the device preserved in a better humidity environment.

[0035] The perovskite films prepared in Comparative Example 1 and Example 1 were aged, and the X-ray photoelectron spectra after aging were measured. The results are as follows: Figure 6 As shown in Figure 1, the perovskite film prepared in Comparative Example 1 showed metal Pb after aging. 0 Characteristic peaks, indicating the formation of a large amount of Pb 0 Defect. Pb 0 As deep level defects, the defects will cause non-radiative recombination of photogenerated carriers, which will greatly damage the photoelectric performance of perovskite solar cells. However, no Pb 0 characteristic peaks, indicating that the addition of 1-thioglycerol can inhibit the 0 The formation of defects.

[0036] In order to further verify the effect of 1-thioglycerol on 2 and metal Pb 0The defect repair ability of metal Pb powder and I 2 The mixture was mixed in the solution, 1-thioglycerol was added to the experimental group, but not to the control group. After 2 hours of stirring and standing for a period of time, no precipitation of metal Pb powder was observed in the experimental group, indicating that the metal Pb had been completely mixed with I 2 Reaction to form PbI 2 In the control group without 1-ThL, after 2 hours of stirring and standing, there was still a lot of Pb powder left at the bottom, indicating that the metal Pb was not completely reacted. Figure 7 As shown, it is proved that 1-thioglycerol can promote the 2 reaction, and 1-thioglycerol and its reaction product can construct a redox shuttle system to achieve I 2 and metal Pb 0 Bug fixes.

[0037] Step 5: Spin-coat a layer of Spiro-OMeTAD film on the surface of the perovskite film to obtain a hole transport layer. Evaporate a silver metal electrode on the surface of the hole transport layer to obtain a formal solar cell based on the addition of 1-thioglycerol.

[0038] The current density-voltage curves of the solar cells prepared in Comparative Example 1 and Example 1 were measured. The results are as follows: Figure 8 The photoelectric conversion efficiency of the solar cell prepared in Example 1 is 25.34%, the open circuit voltage is 1.175 V, the fill factor is 84.27%, and the short circuit current is 25.59 mA cm -2 Compared with the solar cell prepared in Comparative Example 1, it has a more excellent photoelectric conversion performance, indicating that the addition of 1-thioglycerol is helpful for the preparation of perovskite film in an air environment and improves the photoelectric performance of the device.

[0039] At the same time, the perovskite precursor solutions prepared in Comparative Example 1 and Example 1 were aged, and the perovskite layer of the solar cell was prepared using the aged perovskite precursor solution. The current density-voltage curve of the solar cell prepared using the aged perovskite precursor solution was measured. The results are as follows: Figure 8 As shown, it can be seen that the efficiency of the battery prepared by the perovskite precursor solution without 1-thioglycerol addition in Comparative Example 1 is significantly reduced, indicating that the deteriorated perovskite precursor solution is not suitable for continued use. However, the battery prepared by the perovskite precursor solution with 1-thioglycerol added in Example 1 has a current density-voltage curve that is basically consistent with that before aging, proving that the addition of 1-thioglycerol has a prolonging effect on the shelf life of the perovskite precursor solution.

[0040] Comparing the stability of the solar cells prepared in Comparative Example 1 and Example 1, the results are as follows: Fig. 9As shown, after continuous illumination at the maximum power point for 500 hours, the photoelectric conversion efficiency of the solar cell prepared in Example 1 did not decrease substantially, while that of Comparative Example 1 decreased significantly. This indicates that the addition of 1-thioglycerol can enhance the stability of perovskite solar cells, thereby serving more efficiently and for a longer period of time.

[0041] Example 2

[0042] This embodiment prepares a perovskite precursor solution and a formal solar cell based on the addition of 1-thioglycerol, and the specific steps are as follows: Step 1: ultrasonically clean the transparent conductive substrate with deionized water, acetone and ethanol in sequence, and perform plasma treatment on the transparent conductive substrate after drying.

[0043] Step 2: Spin-coat a layer of SnO on the surface of the plasma-treated transparent conductive substrate. 2 The film was then annealed at 150°C for 30 minutes to obtain an electron transport layer.

[0044] Step 3: PbI 2 and 1-ThL were dissolved in N,N-dimethylformamide and dimethyl sulfoxide mixed in a volume ratio of 9:1, and PbI 2 The concentration of is 1.5 mol / L, the concentration of 1-thioglycerol is 0.1 mg / mL, and a perovskite component precursor solution with 1-thioglycerol added is obtained.

[0045] FAI, MACl and 1-ThL were dissolved in isopropanol. The concentration of FAI was 90 mg / mL, the concentration of MACl was 9 mg / mL, and the concentration of 1-thioglycerol was 0.1 mg / mL, to obtain an ammonium salt solution to which 1-thioglycerol was added.

[0046] Step 4: Spin-coat the perovskite component precursor solution with 1-thioglycerol added on the surface of the electron transport layer at a speed of 1500 rpm, and then anneal at 70°C for 60 seconds to form PbI 2 Then on PbI 2 The film surface was spin-coated with an ammonium salt solution with 1-thioglycerol added at a rotation speed of 1800 rpm, and then annealed at 150° C. for 20 minutes to obtain a perovskite film.

[0047] Step 5: Spin-coat a layer of Spiro-OMeTAD film on the surface of the perovskite film to obtain a hole transport layer. Evaporate a silver metal electrode on the surface of the hole transport layer to obtain a formal solar cell based on the addition of 1-thioglycerol.

[0048] Example 3

[0049] This embodiment prepares a perovskite precursor solution and an inverted solar cell based on the addition of 1-thioglycerol, and the specific steps are as follows: Step 1: ultrasonically clean the transparent conductive substrate with deionized water, acetone and ethanol in sequence, and perform plasma treatment on the transparent conductive substrate after drying.

[0050] Step 2: Spin-coat a layer of NiO on the surface of the plasma-treated transparent conductive substrate x film to obtain a hole transport layer.

[0051] Step 3: PbI 2 and 1-ThL were dissolved in N,N-dimethylformamide and dimethyl sulfoxide mixed in a volume ratio of 9:1, and PbI 2 The concentration of is 1.5 mol / L, the concentration of 1-thioglycerol is 0.1 mg / mL, and a perovskite component precursor solution with 1-thioglycerol added is obtained.

[0052] FAI, MACl and 1-ThL were dissolved in isopropanol. The concentration of FAI was 90 mg / mL, the concentration of MACl was 9 mg / mL, and the concentration of 1-thioglycerol was 0.1 mg / mL, to obtain an ammonium salt solution to which 1-thioglycerol was added.

[0053] Step 4: Spin-coat the perovskite component precursor solution with 1-thioglycerol added on the surface of the hole transport layer at a speed of 1500 rpm, and then anneal at 70°C for 60 seconds to form PbI 2 Then on PbI 2 The film surface was spin-coated with an ammonium salt solution with 1-thioglycerol added at a rotation speed of 1800 rpm, and then annealed at 150° C. for 20 minutes to obtain a perovskite film.

[0054] Step 5: Spin-coat a layer of SnO on the surface of the perovskite film 2 The film was then annealed at 150°C for 30 minutes to obtain an electron transport layer. A silver metal electrode was evaporated on the surface of the electron transport layer to obtain a transverse solar cell based on 1-thioglycerol addition.

[0055] Example 4

[0056] This embodiment prepares a perovskite precursor solution and an inverted solar cell based on the addition of 1-thioglycerol. Based on the embodiment 3, C 60 and PC 61 The electron transport layer is prepared by mixing BM materials.

[0057] Example 5

[0058] This embodiment prepares a perovskite precursor solution and an inverted solar cell based on the addition of 1-thioglycerol. On the basis of Example 3, PbI 2 With PbBr 2, CsI, CsBr, and FAI are dissolved in a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide, and 1-thioglycerol is added to prepare a perovskite component precursor solution to which 1-thioglycerol is added.

Claims

1. A perovskite precursor solution based on the addition of 1-thioglycerol, wherein the perovskite precursor solution is a perovskite component precursor solution or a PbI2 solution and an ammonium salt solution, characterized in that: The perovskite component precursor solution contains 1-thioglycerol at a concentration of 0.01-0.5 mg / mL; or the PbI2 solution and the ammonium salt solution respectively contain 1-thioglycerol at a concentration of 0.01-0.5 mg / mL.

2. The perovskite precursor solution based on 1-thioglycerol addition as claimed in claim 1, characterized in that: The concentration of the 1-thioglycerol is 0.1 mg / mL.

3. The perovskite precursor solution based on 1-thioglycerol addition as claimed in claim 1, characterized in that: The perovskite component is PbI2, or a combination of PbI2 and one or more of PbBr2, CsI, and CsBr; the ammonium salt is a combination of multiple of FAI, MAI, MABr, and MACl.

4. A method for preparing a perovskite film based on the addition of 1-thioglycerol, characterized in that: Prepare a perovskite precursor solution based on 1-thioglycerol addition as described in any one of claims 1 to 3, and spin-coat the perovskite component precursor solution in the air by a one-step method, or spin-coat the perovskite PbI2 solution and the ammonium salt solution in the air in a two-step method to prepare a perovskite film.

5. A solar cell based on 1-thioglycerol addition, characterized in that: The perovskite thin film of the solar cell is prepared by the method according to claim 4.

6. A method for preparing a solar cell based on the addition of 1-thioglycerol, wherein an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode are sequentially deposited on the surface of a transparent conductive substrate in air to obtain a formal solar cell, characterized in that: The perovskite layer is prepared by the method according to claim 4.

7. The method for preparing a solar cell based on the addition of 1-thioglycerol as claimed in claim 6, characterized in that: A hole transport layer, a perovskite layer, an electron transport layer and a metal electrode are sequentially deposited on the surface of a transparent conductive substrate to obtain an inverted solar cell.

8. The method for preparing a solar cell based on 1-thioglycerol addition as claimed in claim 6, characterized in that: The electron transport layer is made of TiO2, SnO2, ZnO2, C 60 、PC 61 A film made of one or more composite materials in BM.

9. The method for preparing a solar cell based on the addition of 1-thioglycerol as claimed in claim 6, characterized in that: The hole transport layer is Spiro-OMeTAD, PTAA or NiO x Film made of material.

10. The method for preparing a solar cell based on 1-thioglycerol addition according to claim 6, characterized in that: The metal electrode is one of gold, silver and copper.

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